You may need to reload a page the first time after installing this addon. Double-clicking a regular image just works by itself (note that not everything that looks like a regular image on your screen will be detected as such, but the vast majority will be). The hover button also does not just show in the middle of the page in normal circumstances. but on an image. If this is your experience, you're testing it on just 1 website, and one that happens to do odd things this addon can't support with images. Please try it on other sites too before judging, or open a ticket on gitlab (or email me) and at least link me to the page so I can have a look.